Jump to content
SAU Community

Recommended Posts

I know this may not be the best place (but where else?). Does anybody have a close up of their completed, and *working* Jaycar DFA from top ??

When I first built it, despite being fairly careful, I stuffed the polarity of a diode, which ended up blowing a transistor. Anyhow, so bought another of the same from jaycar, soldered it in, and still not getting any success. Key points I've measured with the multimeter - and getting voltages to various parts - but without a voltage diagram included, can't tell what the values should be in a working circuit.

The handcontroller backlight connects up, but i am just getting a sort of flashing effect, but no display on it. The LED on the DFA lights up and it "clicks" on. The controller is a lot simpler, so more convinced that the DFA is stuffed, rather than the controller (much simpler circuitry). Its a hard one, as its possible another component is stuffed internally, but how do I tell?

I've tried both a standalone 12V power supply.. (old PC powersupply) and connected to my car, and same result.

Whilst I have checked the schematic and my competed version 10 times and cannot spot any differences, an actual high res photo would help a lot, so I can pick off all the right parts and match to mine.

Checked all solders, redone a few that were maybe a bit sus. Don't really want to toss it in the bin without having even tried it :) Really do want to give it a try, as I'd save for a rb20det PFC, but in the end I am swapping to RB25 and would have to onsell it again to get the rb25 PFC.

Any help appreciated..

Link to comment
https://www.sau.com.au/forums/topic/78989-jarcar-fuel-adjuster-some-probs/
Share on other sites

Is the DFA the one where one of the links is shown is the incorrect position in the photo/on the PCB? Maybe it the IEBC, i made them at the same time and cant remember.

How do you tell? Go through with a multimeter and test every solder and link, and triple check everything else... good luck.

mmm... but check what? lol.. I have checked the resistance across the resistors, that is all fine and easy to do.

Check the voltage values of the I/C's.. that would be nice, if I knew exactly how they worked or the exact voltage you should be seeing across each pin at a given point but I don't.

I went through the calibration procedure.. feed in 5v.. checking voltage across TP2.. checking output voltage while adjusting the variable resistors till it was 5V... Checked output signal... its outputting 5v. It seems to be "partly" working.

grunt :)

In the assembly instructions about 5 pages worth, there is a page that list voltages from various IC chips. It also shows where the IC's should have continuity (be joined).

Using that diagram is how i solved one of my problems which was an intermittent operation fault.

I found one of the links didnt have continuity, i checked the links after i didnt measure the correct voltage that the diagram showed.

I've just pulled out the instructions, the diagram you should be fault finding with is on Page 117.

Hope that helps.

digitalfueladjuster1.jpg

my DFA works 100% i have installed and tested it here is a photo 4 u.

Just be patient. its a difficult project especially for a novice like me, but in the end you will get it working.

and the results will be well worth it.

Quick questions for those of you who have tuned you car with the DFA.

How long did it take you to tune it on the dyno?

did you do a power run, look at the AFR's and then tune in view mode? or did you tune on the fly? (this sounds scary to me)

did you disconnect the oxygen sensor while you were tuning?

RB30-power: ok, have page 117. I will see if that can help

Thanks heaps CEF11E for the large photo, I will study that in detail.

Thanks for the help guys.. hopefully I find something.

It didn't seem too hard to assemble and the soldering, etc was fairly easy (have done a bit before) compared to some things, but obviously I have missed something small which is preventing it from working.

That's what makes these things so annoying. It's the fact that one small component or link can be missing or in the wrong place which makes the whole thing not work.

I'm not saying that this is you Pred coz you have experience, but i noticed that in the Jaycar EBC and DFA thread, many people were jumping on the bandwagon because of the cheap and attractive price realising that they couldn't build one and get it working.

They are really not that hard to make, as long as you are careful and check everything with the diagram etc.

That said, it is easy to stuff it up, especially the soldering, its quite fiddely. Go through all the solder joints with a multimeter checking for continuity. Anything on the same metal bit on the PCB should be joined together. I found one of my early solders didnt work (luckily i improved as i went along.)

I don't mean that they're hard to make as such. Just follow the instructions and it's like baking a cake. EXCEPT, it is so easy for things to go wrong.

Solder Joints may look ok, but not contact well, wrong components, faulty components etc, components in the wrong place and many other examples.

I was just saying that it's fiddly and it's not as easy as it seems.

As an example, I have quite a bit of experience with electronics, and I made the jaycar ebc perfectly, but it did not work. Turned out the problem was I had used the wrong cable even though the plugs were the same.

I have soldered a few things, ps2 chips, etc.. the soldering part isn't that hard part.. I even did first year electronics in Uni (fat lot of good that did though :))

I checked all the voltages on the diagram and even they seem pretty much to spec, all resistors have been checked for resistance across each via multimeter. Have resoldered many connections.. The LED is lighting up. I am getting 5V at TP2 after adjusting the variable resistor, apply 5v at source, etc.

I'm half giving up diagnosing as I've spent hours on it.. and buying some replacement parts to try and swap in. First time I put it together, diode round the wrong way... popped a transisitor. Replaced that, and still no go - so must be something else, possibly inside one of the IC's has fried.

Thats a good point re the cable - I used the grey 25 pin cable provided from jaycar and that was recommended as part of the group buy.. Hope its the right one???

Now its really just pissing me off, and when something pisses me off enough I don't stop until I've beat it :Pimp2:

Maybe if you can have someone else look at it? You know what they say about fresh eyes etc.. well i cant really remember but often if youve looked at something a million times you just miss things.

Maybe have another look at your handcontroller? If your pretty sure the DFA is right, perhaps your handcontroller is the problem? Maybe use someone elses handcontroller and see if it works.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Thanks for that, I'll check it all out. I can always do the brakes last anyway if its a problem.  The 16's are super cool, if they do fit I'll cruise around with them for a bit.  
    • Well, that's kinda the point. The calipers might interfere with the inside of the barrels 16" rims are only about 14" inside the barrels, which is ~350mm, and 334mm rotors only leave about 8mm outboard for the caliper before you get to 350, And.... that;s not gunna be enough. If the rims have a larger ID than that, you might sneak it in. I'd be putting a measuring stick inside the wheel and eyeballing the extra required for the caliper outboard of the rotor before committing to bolting it all on.
    • OK, so again it has been a bit of a break but it was around researching what had been done since I didn't have access to Neil's records and not everything is obvious without pulling stuff apart. Happily the guy who assembled the engine had kept reasonable records, so we now know the final spec is: Bottom end: Standard block and crank Ross 86.5mm forgies, 9:1 compression Spool forged rods Standard main bolts Oil pump Spool billet gears in standard housing Aeroflow extended and baffled sump Head Freshly rebuilt standard head with new 80lb valve springs Mild porting/port match Head oil feed restrictor VCT disabled Tighe 805C reground cams (255 duration, 8.93 lift)  Adjustable cam gears on inlet/exhaust Standard head bolts, gasket not confirmed but assumed MLS External 555cc Nismo injectors Z32 AFM Bosch 023 Intank fuel pump Garret 2871 (factory housings and manifold) Hypertune FFP plenum with standard throttle   Time to book in a trip to Unigroup
    • I forgot about my shiny new plates!
    • Well, apparently they do fit, however this wont be a problem if not because the car will be stationary while i do the suspension work. I was just going to use the 16's to roll the old girl around if I needed to. I just need to get the E90 back on the road first. Yes! I'm a believer! 🙌 So, I contacted them because the site kinda sucks and I was really confused about what I'd need. They put together a package for me and because I was spraying all the seat surfaces and not doing spot fixes I decided not to send them a headrest to colour match, I just used their colour on file (and it was spot on).  I got some heavy duty cleaner, 1L of colour, a small bottle of dye hardener and a small bottle of the dye top coat. I also got a spray gun as I needed a larger nozzle than the gun I had and it was only $40 extra. From memory the total was ~$450 ish. Its not cheap but the result is awesome. They did add repair bits and pieces to the quote originally and the cost came down significantly when I said I didn't need any repair products. I did it over a weekend. The only issues I had were my own; I forgot to mix the hardener into the dye two coats but I had enough dye for 2 more coats with the hardener. I also just used up all the dye because why not and i rushed the last coat which gave me some runs. Thankfully the runs are under the headrests. The gun pattern wasn't great, very round and would have been better if it was a line. It made it a little tricky to get consistent coverage and I think having done the extra coats probably helped conceal any coverage issues. I contacted them again a few months later so I could get our X5 done (who the f**k thought white leather was a good idea for a family car?!) and they said they had some training to do in Sydney and I could get a reduced rate on the leather fix in the X5 if I let them demo their product on our car. So I agreed. When I took Bec in the E39 to pick it up, I showed them the job I'd done in my car and they were all (students included) really impressed. Note that they said the runs I created could be fixed easily at the time with a brush or an air compressor gun. So, now with the two cars done I can absolutely recommend Colourlock.  I'll take pics of both interiors and create a new thread.
×
×
  • Create New...